The effect of the internal audit function’s perceived assurance versus advisory purpose on the external auditor’s reliance decision

Purpose - This study aims to examine the extent to which external auditors (EAs) use the work of the internal audit function (IAF) based on the purpose of its primary activities. The authors rely on attribution theory, which suggests that individuals search for meaning when an event occurs. In this setting, the authors explore how the overall (assurance vs advisory) or specific (e.g. risk management and evaluating internal controls) focus of IAF activities influences perceived EA reliance on the IAF’s work. Design/methodology/approach - The authors first explore the research question with data extracted from a broad, longitudinal survey conducted triennially by the national chapters of the Institute of Internal Auditors in Austria, Germany and Switzerland. The data includes responses from 2014, 2017 and 2020 administrations of the survey. The authors conduct a parallel survey with practicing EAs attending two training sessions of a European office of a global network firm. Hypotheses were tested using ordered logistic regression. Findings - Among the chief audit executive (CAE) participants, the authors observe that a balanced or primarily assurance-related purpose of the IAF, relative to a primarily advisory-related purpose, is associated with higher perceived EA reliance. The authors observe similar perceptions of the extent of reliance among the EA participants. Originality/value - With a unique data set of practicing internal auditors from three countries, coupled with a sample of EAs, to the best of the authors’ knowledge, this study is the first to examine differences in EA reliance across the IAF’s primary roles. The study relies on data from three European countries, which differs from prior EA reliance literature with a largely North American focus. Further, comparison between perceptions of EAs and CAEs is a novel approach and this paper’s findings suggest that perceptions of CAEs could be a reliable proxy for EA-intended behavior.